Head to the marked location and talk to Donovan. As usual, wiretap every single corner of the district to make things a whole lot easier before you take on the rackets. After the cutscene, the two point-of-contact locations will be marked in the map. Talk to them to learn more about the two rackets in this district.
Tip: One of the junction boxes will be a bit tricky to find unless you select it as an active objective and you’re on car. It’s located in the underground parking which entrance is located west of the building over the junction’s location. If you're on a vehicle, the game will give you a direction leading to the parking lot.